Ch. 2 - Biological Basis of Behavior

Question 1

Neurons

Answer 1

Individual cells that are the smallest unit of the nervous system

Question 2

Dendrites

Answer 2

Short fibers that branch out from the cell body and pick up incoming messages

Question 3

Axon

Answer 3

Single long fiber extending from the cell body; it carries outgoing messages

Question 4

Nerve (tract)

Answer 4

Group of axons bundled together

Question 5

Myelin Sheath

Answer 5

White fatty covering found on some axons; provides insulation, protection

Question 6

Sensory (Afferent) Neurons

Answer 6

Carry messages from sense organs to the spinal cord or brain

Question 7

Motor (Efferent) Neurons

Answer 7

Carry messages from the spinal cord or brain to the muscles and glands

Question 8

Interneurons (Association Neurons)

Answer 8

Carry messages from one neuron to another

Question 9

Mirror Neurons (Behavioral)

Answer 9

Specialized neurons that respond when we observe others perform a behavior or express an emotion

Question 10

Glial Cells

Answer 10

Hold neurons together, provide nourishment, removed waste, prevents substances from entering brain, form the myelin sheath

Question 11

Ions

Answer 11

Electrically charged particles found both inside and outside the neuron

Question 12

Resting Potential

Answer 12

Electrical charge across a neuron membrane resulting from more positive ions concentrated on the outside and more negative ions on the inside

Question 13

Depolarization

Answer 13

When a small area of the cell membrane is adequately stimulated by an incoming message, pores in the membrane open, allowing an inflow of positively charged ions

Question 14

Neural Impulse (Action Potential)

Answer 14

The firing of a nerve cell

Question 15

Graded Potential

Answer 15

A shift in the electrical charge in a tiny area of a neuron

Question 16

Threshold of Excitation

Answer 16

The level an impulse must exceed to cause a neuron to fire

Question 17

All-Or-None Law

Answer 17

Principle that the action potential in a neuron does not vary in strength; either the neuron fires at full strength or not at all

Question 18

Absolute Refractory Period

Answer 18

The small period after firing that the neuron will not fire again

Question 19

Relative Refractory Period

Answer 19

When the cell is returning to a resting state

Question 20

Synaptic Cleft

Answer 20

Tiny gap between the axon terminal of one neuron and the dendrites or cell body of the next neuron

Question 21

Synapse

Answer 21

Area composed of the axon terminal of one neuron, the synaptic space, and the dendrite of cell body of the next neuron

Question 22

Terminal Button (Synaptic Knob)

Answer 22

Structure at the end of an axon terminal branch

Question 23

Synaptic Vesicles

Answer 23

Tiny sacs in a terminal button that release chemicals into the synapse

Question 24

Neurotransmitters

Answer 24

Chemicals released by the synaptic vesicles that travel across the synaptic space and affect adjacent neurons

Question 25

Receptor Sites

Answer 25

Locations on a receptor neuron into which a specific neurotransmitter fits like a key into a lock

Question 26

Neural Plasticity

Answer 26

Ability of the brain to change in response to experience

Question 27

Neural Networks

Answer 27

A group of neurons that are functionally connected

Question 28

Neurogenesis

Answer 28

The growth of new neurons